Radiation Damage of Tissues
The extent and progression over time of tissue damage following radiation depends on the amount of radiation and the fractionation schedule.

Following acute effects, chronic changes may occur which are characterized by a deterioration in the small blood vessels, cells, and fibrosis of tissue. Atrophy and ulceration of soft tissues aggravated by trauma and infection are possible further changes.

Surgery in irradiated tissue can prove to be a major problem with poor tissue healing.

Radiation injury with impaired healing can occur early after therapy but most often appears three to four years after treatment. Following radiation of the breast area it is not uncommon to see progressive chronic degeneration for 10 years or more.

In bone, blood vessels are also damaged by radiation and is accompanied by death of bone cells. These changes lead to osteonecrosis and porosis.

Treatment with Hyperbaric Oxygen Therapy
Clinical challenges following radiation injury vary widely, including non-healing ulcers and/or the appearance of sequestrated bone.

In the mouth and face these may be aggravated by irritation from dental appliances or prostheses.

At any site surgical efforts to cover deficiencies by skin grafts or reconstruction may be complicated by failure to heal.

Hyperbaric oxygen therapy (HBO) was introduced more than 20 years ago to improve the chances of successful healing in the presence of radiation effects. It is now recognized as an important adjunctive therapy.

Rationale for Hyperbaric Oxygen Therapy
Progressive changes in walls of blood vessels in irradiated tissues (proliferative endarteritis) leads to a decline in the delivery of oxygen and nutrients. Hyperbaric Oxygen Therapy (HBO) provides a cyclic increase in tissue oxygen levels that promotes collagen formation by fibroblasts and capillary ingrowth.

These processes allow closure of small defects in irradiated tissue and provide an enhanced vascular bed for healing. This includes improved healing in the event of surgery, graft or flap placement.

• Inflammation should diminish and wounds assume a noninfected appearance.
• Increased mucosal covering or regression in ulcer size should occur.
• Decrease in amount of exposed bone which is a sign of healing.
• Improvement in pathological x-ray changes may be recognized.

2. Transcutaneous oxygen measurements may be carried out in affected areas to forecast efficacy of HBO therapy.

3. HBO is done in conjunction with existing treatment.

4. Certified HBO physicians and respiratory therapist in attendance during treatments.

5. A series of photographs of lesions are taken to monitor treatment.

6. The hyperbaric chamber is large enough to accommodate up to six patients comfortably in addition to a therapist, who accompanies patients on all treatments.

7. Our Hyperbaric Medicine Service has experience with over 3500 treatments in the treatment of radiation damaged tissues. Results of healing have been consistently satisfactory.

Typical Treatment Regime with Minimal Number of Treatments
A standard treatment uses 100 percent oxygen (with air breaks) at 2.4 atmospheres for 90 minutes.

• Wounds and grafts - a minimum of 20 treatments is recommended. Post operative treatments may be indicated when necessary
• Prevention of osteonecrosis for tooth extraction in irradiated areas - 20 treatments, extraction - 10 treatments.
• Healing of oro-cutaneous fistula - 30 treatments
• Augmentation of elective-maxillo-facial reconstruction - 20 treatments, surgery - 10 treatments
• Treatment of osteoradionecrosis of mandible- Marx-Univ. of Miami Protocol - Stages II, III, IIIR - 20 treatments - Surgery - 10 treatments
• Healing of tissue radionecrosis - areas other than head and neck -a minimum of 20 treatment

Referring a Patient and Preliminary Work-Up
If you have questions or would like to refer a patient call 319-356-8220 or call UI Hospitals and Clinics' information at 319-356-1616. Ask for the hyperbaric medical doctor.e.